Pneumatic hammer.



Nm 662,993.. Patented-Dec. 4, |900.

` n. s. wAueH.

PNEUMATIC HAMMER. 4

(Application filed Nov. 15, 1899.) (No Marini.)

l. il 'l www 'ANITED STATES PATENT OFFICE.

p DANIEL SHAW WAUGH, OF MARION, OHIO.

PN EUMATIC HAMMER.

SPECIFICATION forming' part of Letters Patent No. 662,993, dated December 4, 1900- .Application filed November l5, 1899. Serial No. 737,105. @lo model.)

To all whom t mag/concern,.-

Be it known that I, DANIEL SHAW WAUGH, a citizen of the United States, residing at Marion, in the county of Marion and State of Ohio, have invented a new and useful Pneumatic Hammer, of which the following is a specification.

This invention relates to automatic hammers, and comprises a recipcatory piston or hammer proper which is adapted to be operated by compressed air, gas, or other suitable motive agent under compression admitted to the casing in which the piston or hammer proper reciprocates.

The object of the invention is to produce a long-stroke valveless hammer without the necessity of employing small parts which are liable to become broken or get out of order.

By means of the construction hereinafter described a colnparatively reduced pressure is provided at the beginning of the eective stroke of the hammer, which pressure increases toward the final end of said stroke, thus enabling the hammer to be reciprocated with but slight vibration to the casing and the handle by means of which the device as a whole is held by the workmen.

Other objects and advantages of the invention will appear in the course of the ensuing description. p

The invention consists'in an automatic hammer embodying certain novel features and details of construction and arrangement of parts, as hereinafter fully described, illustrated in the drawings, and incorporated in the claims. Y

In the accompanying drawings, Figure 1 is a longitudinal section througha hammer constructed in accordance with the present invention, showing the hammer proper at the lower or outer end of its stroke. Fig. 2 is a similar view showing the hammer at the reversed end of its stroke. Fig. 3 is a cross-section through the hammer, taken on the line X X of Fig. 1.

Similar numerals of reference designate corresponding parts in all the figures of the drawings.

In carrying out the present invention I employ a shell or casing 1, which comprises an interior main chamber 2, having intermediate its ends an expansion-chamber 3 and also having at its lower or outer end a supply-chamber 4, which communicates with a longitudinal supplypassage 5, extending alongside the chamber 2, but separated therefrom by an intervening web or wall 6. At its inner or upper end the passage 5 communicates with a transverse supply-passage 7 by means of an oblique connecting bore or opening S. The transverse supply-passage 7 is formed in the head of the casing, which head is indicated by the numeral 9, the same being threaded upon the main body of the shell or casing, as shown at l0, or secured thereto in any approved manner. The passage 7 is reduced to form a conical valve-seat 1l, against which is seated a valve 12, the stem 13 of which extends lengthwise of the passage 7 and terminates in an end knob 14, and by pressing -inward upon which the workmen may unseat the valve for allowing the air orA other motive agent to pass to the piston or hammer proper. The open end of the passage 7 is adapted to receive or have coupled thereto a supply-pipe. (Not shown.) The head 9 is also provided with a suitable handle 15, by which the instrument as a whole is held while it is performing its work. The shell or casing l is further provided with an exhaust-chamber 16, having au exhaust-port 17, opening through the side of the casing.

Within the shell or casing 1 is arranged a hollow piston or hammer proper, (indicated at 1S.) This hammer is closed at its lower end, as at 19, which end forms the strikingsurface of the hammer, While the other end is left open. The central bore of the harnmer terminates at its lower end in a pressure- Vsurface 2O and is enlarged intermediate its ends Vto form a conical pressure-surface 21, while theV inner or upper edge or end 22 of the hammer forms an additional pressuresurface. The air or other motive agent acts upon all of the surfaces 20, 2l, and 22 in irn-j parting the effective or down stroke to the hammer. The hammer is also provided with an exterior pressure shoulder 23, against which the motive agent acts in moving the hammer in one direction, and said shoulder is so disposed that when the hammer is at the lower or outer limit of its movement it enters or lies adjacent to the supply-chamber 4, so

as to receive the upward pressureof the mo-4 IOO i sure-surfaces 20, 21, and 22, so that when the compressed air, gas, or other motive agent acts upon the surfaces 20, 21, and 22 the pressure thereon will overcome the pressure on the comparatively small pressure-surface or shoulder 23. The hammer is further provided near its upper end with induction-ports 24 and near its lower end with eductionports 25.

The head 9 is provided on its under side with a cushion-plug 26, which is of smaller diameter than the internal diameter of the chamber 2, so as to leave a surrounding annular space 27, in which the upper portion of the hammer is received when it reaches the upper limit of its movement, the cushionplug 26 practically filling thek enlarged portion of the bore at the upperend of the hammer 18. The enlarged portion or upper end of the hammer 18 corresponds in diameter with the internal diameter of the chamber 2 and is adapted to pass across the expansionchamber 3,which is in reality an enlargement of the main chamber 2, being offset laterally therefrom, as clearly illustrated inthe drawings, and located intermediate the ends of the chamber 2.

The lower or outer end of the casing 1 is reduced and tapered, as shown at 28, to receive a tapered bit-socket 29, in which is received the shank 30 of a bit 31 of any desired construction.

The operation of the hammer is as follows: The operator presses inward upon the knob 14 and unseats the valve 12, whereupon the compressed air or other motive agent passes through the passages 8 and 5 to the supplychamber 11, where it acts upon the pressureshoulder 23 to elevate the hammer 18. The hammer moves upward or inward until the shoulder 23 reaches the expansion-chamber 3, whereupon the air rushes into the expansionchamber and through the induction-ports 24,

filling the interior of the hammer and' expandl ing between the cushion-plug 26 and the pressure-surfaces 20 and 21 within the hammer. As the hammer begins to move downward the upper end 22 of the hammer ork plunger passes the plane of the expansion-chamber, and the compressed air confined within said expansion-chamber 3 acts to increase the forward or downward impetus of the hammer, enabling it to impart a sharp blow upon the shank of the bit. As the hammer strikes the shank of the bit the eduction-ports 25 register with the exhaust chamber 16 and the-air exhausts through the port 17. Pressure within the chambers 2 and 3 being relieved, theair immediately acts upon the pressureshoulder 23 to again lift the hammer.

By means of the construction above described it will be seen that a comparatively reduced pressure is obtained at the commencement of the downstroke of the hammer, thus causing but slight vibration as the direction bll. stroke for the hammer without the use of are liable to get out of order.

of movement of the hammer is reversed. By means of the expansion-chamber the pressure is augmented toward the end of the downward stroke 0f the hammer and prior to the period of thel hammer striking against the Thus I am enabled to provide a long valves and other small operative parts Which rest the operation of the hamlner, it is only necessary to relieve the pressure on the knob f1/1, when the air-pressure will seat the valve 12 and hold the same'closed until it is again desired tothrow the hammer into operation.

From the'foregoing it is thought that the construction, operation, and many advantages of the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion, and minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention. I

Having thus describedl the invention, what is claimed as new, and desired to be secured by Letters Patent, is-

1. An automatic hammer comprising a casing provided with separate interior supplychamber and an expansion-chamber spaced apart, and a tubular reciprocatory hammer working Within the casing, said hammer being open at one end and provided with induction and eduction ports, and also having an exterior shoulder of less area than the remaining surface exposed to the motive agent, substantially as set forth.

2. In au automatic hammer, a casing having an expansion-chamber located intermediate the ends of the main chamber in which the hammer reciprocates, vthe said expansionchamber being offset laterally from the main chamber, substantially as specified.

3. An automatic ham mercomprising acasing provided with separate interior supply and expansion chambers spaced apart, and a tubular reciprocatory hammer working within the casing, said hammer being open at its inner end, and provided with induction and eduction ports and having an exterior shoulder of less area than the remaining surface exposed to the motive agent, and a cushionplugA arranged to enter the open end of the hammer at the inner or upper end of the stroke of the hammer, substantially as speciied.

11. An automatic hammer comprising a cas- Ving provided with the separate interior supply-chamber and expansion-chamber spaced apart, and also provided near one end with a transverse supply-passage, a pressure-seated vvalve with its stem disposed lengthwise'of said passage and projecting outside of the casing, and a hammer or plunger slidably fitted within the casing and reciprocated solely by the pressure of the motive duid admitted to the latter, as and for thepurposes set forth.

In order to ar- IOO IOS

IIO

ceases 45, In aifluid-actuated hammer, the combination of a casing having means for admitting 'and exhausting motive fluid, a hollow plunger or hammer provided With ports and slidably fitted Within the casin g for reciprocation solely by pressure of motive fiuid therein, said plunger or hammer serving as a Valve to control the admission and exhaust of the motive fluid, and means for reducing the area of the surface on said plunger exposed to the pressure of the motive fluid at one limit of movement of said plunger or hammer Within the casing, as and for the purposes set forth.

6. In a Huid-actuated hammer, the combination of a casing having an expansion-chamber, and means for admitting and exhausting motive fiuid, and a hollow plunger or hammer provided with ports and slidably fitted Within said casing to traverse the expansion-chamber and to control the admission and exhaust of motive fluid to and from the saine, said plunger or hammer being reciprocated solely by the pressure of motive fluid against variable areas of Working faces on the plunger, and the latter also controlling the admission and exhaust of motive fluid to and from the casing, as and for the purposes set forth.

7. In a Huid-actuated hammer, the combination of a casing provided With a projecting portion and having a supply-passage and provided with an exhaust-port, and a reciprocating plunger or hammer provided at its head with an expansion-cham ber to receive the projecting portion and having an opening or passage communicating With the chamber and adapted to communicate also with the exhaust-port, substantially as described;

8. In a duid-actuated hammer, the combination of a casing provided With a supplypassage and exhaust-port and having a projecting portion, and a reciprocating plunger or hammer having an expansion-chamber to receive the projecting portion and provided with an opening or passage communicating with the chamber and adapted to communicate With the exhaust-port, said hammer or plunger being provided With an exterior shoulder, substantially as and for the purposes described.

4 9. In a fluid-actuated hammer, the combination of a casing having a longitudinal supply-passage and provided with an exhaustport, a reciprocating hammer or plunger having an expansion-chamber and provided With a longitudinal opening extending from the said chamber and adapted to register with the exhaust-port at the end of the stroke, said hammer or plunger being provided With an exterior shoulder, and a plug arranged Within the casing and having a reduced portion adapted to extend into the expansion-chamber at the inner portion of the stroke, substantially as described.

l0. In a fluid-actuated hammer, the combination of a casing having a supply-passage and provided with an exhaust-port, a valve for controlling the admission of air, a reciprocating hammer or plunger having an expansion-chamber at its head and provided with a longitudinal opening communicating with the chamberand having transverse apertures, said hammer or plunger being provided With an exterior shoulder, and a plug arranged Within the casing and adapted to extend into the expansion-chamber to reduce the area of pressure at the head of the hammer or plunger, substantially as described.

11. In a huid-actuated hammer, the combination of a casing, a reciprocating plunger or hammer provided at its head With an expansion-chamber, and a plug mounted Within the casing and arranged to extend into the expansion-chamber at the inner portion of the stroke of the hammer or plunger, whereby the area of pressure at the head of the same is reduced, substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two Witnesses.

DANIEL SHA\V WAUGH.

Witnesses:

FRENCH CROW, DJR. CRIssING, Sr. 

